Vistumbler is an excellent program to detect wireless networks and hotspots. Vistumbler was originally made for Windows Vista but now works with Windows 7 flawlessly. With live Google Earth tracking, you can add a GPS to your laptop and map out wireless networks. Vistumbler speaks the signal to you as you walk or drive and marks Google Earth, placing details of each access point. It is illegal to connect to an AP if it is not a public wireless AP. Many business have access points marked as being for ‘Patrons Only’ . The function of this program can be used for measure your business access points or marking access points that for the general public.
As shown in the slideshow below, you can import the information into Google Earth. You can zoom down to each access point (AP) and get details about the AP.
During this session, I used a Microsoft Pharos GPS ($18 on Amazon).